Multi-eye image pickup apparatus and adjusting method

• US 7,956,886 B2
• Filed: 05/23/2008
• Issued: 06/07/2011
• Est. Priority Date: 07/09/2007
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Murayama, Jin
• Primary Examiner(s): Ometz; David L
• Assistant Examiner(s): Chon; Peter
• Application Number:
  US12/126,659
• Publication Number:
  US 20090015689A1
• Time in Patent Office: 1,110 Days
• Field of Search: 348/42, 348/46, 348/48, 348/51, 348/52, 348/53, 348/207.99, 348/222.1, 348/223.1, 348/224.1, 348/229.1, 348/230.1, 348/234, 348/333.01, 348/333.02, 396/322, 396/324, 396/325, 396/326, 396/327, 396/333, 396/334
• US Class Current: 348/42
• CPC Class Codes: H04N 13/133 Equalising the characteristics of different image components, e.g. their average brightness or colour balance
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/246 Calibration of cameras
• CPC Class Codes: H04N 13/25 using two or more image sensors with different characteristics other than in their location or field of view, e.g. having different resolutions or colour pickup characteristics; using image signals from one sensor to control the characteristics of another sensor
• CPC Class Codes: H04N 13/257 Colour aspects
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof

Abstract

A stereoscopic camera includes a master camera for photoelectric conversion of object light to generate a first image signal with three color components G, R and B. A slave camera generates a second image signal. In an adjusting method, a first gain Dmr, Dmg and Dmb of the color components is determined according to the first image signal to correct a brightness level and white balance of the master camera, to adjust the first image signal by use thereof. A second gain Dsr, Dsg and Dsb of the color components is determined according to the first gain and color calibration information predetermined according to color sensitivity of the master and slave cameras in relation to the color components. The second image signal is adjusted by use thereof, for color matching between the first and second image signals to set equal the brightness level and the white balance.

Claims

1. A multi-eye image pickup apparatus, including a first image pickup assembly having a first image sensor for photoelectric conversion of object light to generate a first image signal with plural color components, and at least one second image pickup assembly having a second image sensor for photoelectric conversion of said object light to generate a second image signal with plural color components, said multi-eye image pickup apparatus comprising:

a memory for storing color calibration information defined in association with color sensitivity of said first and second image sensors for said plural color components;

a first corrector for adjusting said first image signal for respectively said plural color components, to correct a brightness level and white balance;

a second corrector for adjusting said second image signal for respectively said plural color components, to correct a brightness level and white balance;

a first gain setting unit for determining a first gain according to said first image signal, and for assigning said first corrector therewith; and

a second gain setting unit for determining a second gain according to said first gain and said color calibration information, and for assigning said second corrector therewith, to set equal said brightness level and said white balance between said first and second image signals.

2. A multi-eye image pickup apparatus as defined in claim 1, wherein said second gain setting unit assigns said second gain in synchronism with assignment of said first gain by said first gain setting unit.

3. A multi-eye image pickup apparatus as defined in claim 2, further comprising:

a first amplifier for amplifying said first image signal between said first image sensor and said first corrector, to correct a brightness level thereof;

a second amplifier for amplifying said second image signal between said second image sensor and said second corrector, to correct a brightness level thereof;

a third gain setting unit for determining a third gain according to said first image signal, to assign said first amplifier with said third gain; and

a fourth gain setting unit for determining a fourth gain according to said third gain, to assign said second amplifier with said fourth gain.

4. A multi-eye image pickup apparatus as defined in claim 3, wherein said first and second gain setting units assign said first and second gains in a frame period after said third and fourth gain setting units assign said third and fourth gains.

5. A multi-eye image pickup apparatus as defined in claim 1, wherein said color calibration information is predetermined by image pickup of one test object with said first and second image pickup assemblies in a common measuring condition.

6. A multi-eye image pickup apparatus as defined in claim 5, wherein said color calibration information is constituted by a relative sensitivity value of a green color of colors of said plural color components, and a ratio of a relative sensitivity value of red and blue colors to said relative sensitivity value of said green color for each of said first and second image pickup assemblies.

7. A multi-eye image pickup apparatus as defined in claim 5, wherein said color calibration information is constituted by a ratio of a relative sensitivity value of said first image pickup assembly to a relative sensitivity value of said second image pickup assembly for respectively said plural color components, and said first gain is multiplied by said ratio to determine said second gain.

8. An adjusting method of adjusting a multi-eye image pickup apparatus including a first image pickup assembly for photoelectric conversion of object light to generate a first image signal with plural color components, and at least one second image pickup assembly for photoelectric conversion of said object light to generate a second image signal with plural color components, said adjusting method comprising steps of:

determining a first gain of said plural color components according to said first image signal to correct a brightness level and white balance of said first image pickup assembly, to adjust said first image signal by use thereof; and

determining a second gain of said plural color components according to said first gain and color calibration information predetermined according to color sensitivity of said first and second image pickup assemblies in relation to said plural color components, to adjust said second image signal by use thereof, for color matching between said first and second image signals to set equal said brightness level and said white balance.

9. An adjusting method as defined in claim 8, wherein said second gain is assigned in said second image pickup assembly in synchronism with assignment of said first gain in said first image pickup assembly.

10. An adjusting method as defined in claim 9, further comprising steps of:

before adjusting said first image signal with said first gain, amplifying said first image signal with a third gain determined according to said first image signal, to correct said brightness level thereof;

before adjusting said second image signal with said second gain, amplifying said second image signal with a fourth gain determined according to said third gain, to correct said brightness level thereof.

11. An adjusting method as defined in claim 10, wherein said first and second gains are assigned in a frame period after said third and fourth gains are assigned.

12. An adjusting method as defined in claim 8, wherein said color calibration information is predetermined by image pickup of one test object with said first and second image pickup assemblies in a common measuring condition.

13. An adjusting method as defined in claim 12, wherein said color calibration information is constituted by a relative sensitivity value of a green color of colors of said plural color components, and a ratio of a relative sensitivity value of red and blue colors to said relative sensitivity value of said green color for each of said first and second image pickup assemblies.

14. An adjusting method as defined in claim 12, wherein said color calibration information is constituted by a ratio of a relative sensitivity value of said first image pickup assembly to a relative sensitivity value of said second image pickup assembly for respectively said plural color components, and said first gain is multiplied by said ratio to determine said second gain.